See here. Their answer seems to be: Not really. The stock has broken through $600 and is headed for $700. Stock is trading at 50x earnings. Even Fred Hickey, notorious curmudgeon, says he doesn’t dare short it because the mania is too strong. So what could tip them over? Money quote: “The potential threats, according to industry analysts, fall into three broad categories: those from inside the company, those from rivals, and public policy challenges that could bring regulatory controls and tarnish Google’s reputation and brand.”

One factor the Times leaves out: The looming exodus of a lot of very important people who are about to get unlocked, stock-wise. It’s all Squirrel Boy talks about these days. And it will be the big story of 2008.